| 多环芳烃在西江高要段水体中的分布与分配 |
| 摘要点击 2606 全文点击 2348 投稿时间：2008-12-02 修订日期：2009-05-31 |
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| 中文关键词 多环芳烃 西江 溶解相；颗粒相；分配；分配系数 |
| 英文关键词 polycyclic aromatic hydrocarbons (PAHs) Xijiang River dissolved phase particle phase partition partition coefficient |
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| 中文摘要 |
| 为了解西江流域水体中多环芳烃(PAHs)的深度和季节分布及其在溶解相和颗粒相的分配以及控制因素，分别在洪水期（2003年8月和2004年7月）和枯水期（2003年11月和2004年3月）采集了西江高要段水柱.结果表明，溶解相和颗粒相中PAHs的浓度分别为21.7～138 ng/L和40.9～664.8 μg/kg; 水体中PAHs的总含量（颗粒相及溶解相），洪水期大于枯水期.在溶解相中，PAHs的浓度随深度无明显规律；而在颗粒物中，PAHs的浓度都表现出相同的变化趋势, 即中层水PAHs含量最高,表层水PAHs含量最低.溶解相和颗粒相中PAHs的浓度都随悬浮颗粒物的含量增加而增加.从PAHs组成特点来看，溶解相以3环的PAHs为主, 而颗粒相以3～4环的PAHs为主.PAHs在颗粒相及溶解相中的分配系数(KP)不受颗粒有机碳浓度控制（R2为0.000 1～0.2），而受颗粒物浓度、及溶解有机碳浓度的共同影响（R2为0.15 ～0.36），尤其是溶解态的细小碳黑有机质的影响. 西江高要段水体PAHs在不同季节的lgKOC值大部分超过经典平衡分配模型的上限. 除了2003年11月（R2为0.000 4～0.12, p < 0.001）之外，其它3个季节PAHs的lgKOC与 lgKOW均有较强的相关性（R2为0.29～0.91, p<0.05）. 洪水期颗粒物的亲脂性强于枯水期. |
| 英文摘要 |
| To obtain the seasonal and vertical distribution and partition of PAHs between dissolved phase and particle phase in Xijiang River basin, water columns were collected during flood seasons (August, 2003 and July, 2004) and dry seasons (November, 2003 and Mar, 2004) from Gaoyao section of Xijiang River. The average PAHs concentrations in dissolved phase and particle phase were 21.7-138 ng·L-1, 40.9-664.8 μg·kg-1, respectively. Total PAHs concentrations (both particle phase and dissolved phase) were higher in flood seasons than that in dry seasons. No variation was found for dissolved PAHs in vertical distribution However, a same trend of vertical distribution was observed for particle PAHs with the maximum concentration in middle layer and minimum in surface layer of water column. With increasing of content of suspended particle matter (SPM), both dissolved and particle PAHs concentration increased. In the dissolved phase, the predominant PAHs were 3 ring PAHs. While in the particle phase, 3-4 ring PAHs were the dominant PAHs. The partition coefficient (KP) had no correlation with the particle organic carbon content of SPM（R2 0.000 1-0.2）, but influenced by concentrations of suspended particle matters and dissolved organic carbon, especially black carbon in dissolved phase（R2 0.15 -0.36）. A majority of values of lg KOC in different seasons exceeded upper limit based on typical model of equilibrium distribution. Except the season of November 2003（R2 0.000 4-0.12, p<0.001）, the organic carbon normalized distribution coefficients (KOC) computed for the PAHs were correlated well with their octanol-water partition coefficient (KOW)（R2 0.29-0.91, p< 0.05）. The lipophilic ability of SPM was stronger in flood seasons than that in dry seasons. |
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